1. Field of the Invention
This invention relates to the field of food preparation. More particularly, this invention relates to an apparatus and method for maintaining in a ready-to-serve condition cooked food portions contained in a food tray, wherein a freestanding cover is used to cover the food trays.
2. Description of Related Art
In many establishments, such as fast food restaurants, certain food items are cooked well in advance of when they are ordered by or served to the customer. Examples of such food items can include sandwich fillings, such as cooked eggs, hamburger patties, breaded foods, such as chicken nuggets, or baked goods, such as muffins. These previously cooked food items are often maintained in a ready-to-use or ready-to-serve condition until they are served to the customer. This typically involves maintaining the previously cooked food items at a serving temperature in the range of from about 145° F. to about 200° F., depending on the food item.
Various food warming apparatus have been developed to maintain previously cooked food items at a desired serving temperature. Such food warming apparatus are sometimes referred to as staging cabinets, holding cabinets, or warming cabinets. One of the challenges associated with food warming apparatus is being able to preserve the flavor, appearance, and texture of the previously cooked food items while they are being maintained at the desired serving temperature. In particular, certain types of food items, such as cooked eggs and hamburger patties have a tendency to dry out undesirably then they are kept warm for extended periods of time. Other types of food items, such as fried foods, have a tendency to become undesirably soggy when they are kept warm for extended periods of time.
One commonly used way to protect previously cooked food items for which drying out is a concern, is to place the food items in a container, such as a tray, and to provide a cover for the container. The cover restricts evaporation of moisture from the previously cooked food items. With a reduced amount of moisture vapor being able to escape from the covered container, the previously cooked food items contained therein do not dry out as rapidly.
Conventional covers are inconvenient to use in food fast restaurants and similar establishments. This is because when previously cooked food portions are taken from the food warming apparatus, the cover typically must be removed from the tray to gain access to the food items contained therein, and must be replaced to protect the remaining food portions contained in the tray. The steps of removing and replacing a cover can take an amount of time that is unacceptably large in fast food restaurants. The removed cover can become misplaced or contaminated and can get in the way of other activities in the kitchen area.
Food warming apparatus that do not require a separate cover the food trays have also been developed. For example, U.S. Pat. Nos. 5,783,803 and 5,900,173 to Robards disclose a food warming apparatus in which a grate supports the food trays in a warming cavity. A seal is operatively associated between the top of the tray and the ceiling of the cavity. The grate includes a biasing portion that biases the tray upwardly so that it seals against the ceiling. The advantage of providing a seal in this manner is that evaporation of liquid from previously cooked food portions contained in the trays is greatly reduced. A disadvantage with this approach, however, is that the components required to provide the seal can be costly, complex, or difficult to clean.
A modification of this approach has been used in which the grate biases the food tray towards the ceiling of the warming cavity such that the lip of the tray touches, or nearly touches, the ceiling without necessarily forming a seal. It has been that evaporation is sufficiently restricted in this configuration, even though no seal is formed.
Another approach is disclosed in U.S. Pat. Nos. 5,724,886 and 5,947,012 to Ewald, et al. These patents disclose a food staging device having a plurality of compartments, with each compartment bounded by an upper heated compartment surface and a lower heated compartment surface. The trays containing previously cooked food portions are sized such that the top edges are within zero to 0.25 inches from the upper heated compartment surface. This zero to 0.25 inch distance is said to be sufficient to restrict evaporation of liquid form the food portions contained in the trays.
A disadvantage with the approach disclosed in these patents is that once the distance between the upper and lower compartment surfaces is set, a tray within a particular size range must be provided in order for its top edge to be within zero to 0.25 inches from the upper compartment surface. Another disadvantage with this approach is that for previously cooked food items for which sogginess is a concern, air circulation should be encouraged, rather than restricted. Accordingly, these patents disclose that different trays may be used, depending on whether the previously cooked food portions tend to dry out or tend to become soggy.
Moreover, a disadvantage with the general approach of bringing the food tray close to the heated cavity ceiling or heated upper compartment surface is that the heated surface transmits heat radiatively into the food tray. This radiant heat can affect the flavor, appearance, and texture of food items located near the top of the tray, even though evaporation from the tray is restricted.
U.S. Pat. No. 5,852,967 to Fortmann, et al., discloses yet another a food warming apparatus comprising a frame having first and second walls. At least one of the first and second walls is movable relative to the other in order to vary the spacing between them. Trays containing previously cooked food items are placed between the first and second walls, so that the first wall bears the tray, and the second wall at least partially blocks the open top of the tray. A disadvantage with this approach, however, is that the moving parts required to provide the movable wall can be difficult to maintain. Another disadvantage with the approach is that it does not easily allow trays of different sizes to be placed in the same compartment.
Accordingly, what is needed is a food warming apparatus that has the flexibility to be able to maintain in a ready to use condition both cooked food items that tend to dry out and cooked food items that tend to become soggy, and to use trays of various sizes, as may be needed to meet the rapidly changing demands that can occur in fast food restaurants or similar establishments. The food warming apparatus should also be inexpensive to construct, and easy to use and to maintain.